Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M103/00—Lubricating compositions characterised by the base-material being an inorganic material

Definitions

• the invention relates to a novel lubricant composition which is suitable for preventing carburization on the inner surface of the tube blanks in the production of seamless pipes, and to processes of preventing such carburization.
• the main object of the invention is to provide a suitable lubricant which effectively prevents carburization.
• Other objects and advantages of the invention are set out herein or are obvious herefrom to one skilled in the art.
• the lubricant composition of the invention comprises:
• Suitable graphites are very finely divided synthetic graphites having a mean particle size d 50 of 1 ⁇ m to 10 ⁇ m.
• the particle upper limit is expediently 8 ⁇ m to 50 ⁇ m.
• the graphites employed are distinguished by a high purity of ⁇ 99 percent and a crystallinity Lc ⁇ 60 nm.
• Particularly preferably are the finely divided KS types (of graphite) from Timcal, Ltd., Bodio, Switzerland, are employed; for example, in particular KS 6, KS 10 or KS 15 (graphites) are especially preferred.
• the clay minerals from the smectite classes essentially comprise sheet silicates and as a result of their structure are distinguished by a high cation exchange capacity and by a high swellability in water.
• montmorillonites are preferably used, in particular those which have a swelling capacity (1 g of montmorillonite with distilled water) of 10 to 50.
• the primary particle size (with complete dispersion) is also essential, so that a smectite having a mean particle size d 50 of 1 ⁇ m to 10 ⁇ m is expediently used.
• a silica sol is taken to mean a colloidal solution of SiO 2 -particles having a mean particle size d 50 of 6 nm to 30 nm in water.
• the solid content of the such sol is expediently between 30 percent by weight and 40 percent by weight.
• the silica sol has an Na 2 O content of 0.15 percent to 0.4 percent and a specific BET surface area of approximately 200 m 2 /g to 300 m 2 /g.
• potassium aluminum silicate includes a sheet or leaf silicate occurring under the mineral name mica.
• a mica of the muscovite type is expediently employed.
• the finely divided character is also essential here, so that a mica having a mean particle size d 50 of 5 ⁇ m to 10 ⁇ m is expediently used.
• the lubricant composition of the invention can be prepared in an application- and customer-based manner in two fundamental formulations, either as a ready-to-use dispersion or as a powder which the customer himself disperses.
• a lubricant composition which is suitable for a ready-to-use dispersion expediently comprises:
• This lubricant composition is advantageously processed with water in conventional dispersion apparatuses which make high shearing forces possible, to give an aqueous dispersion having a solids content of 20 percent to 35 percent.
• the viscosity of this dispersion (Rheomat 15, System B, 20° C., speed 5) within the range 1000 MPas to 4000 MPas.
• a lubricant composition which is suitable for a powder which the customer himself disperses expediently comprises:
• This lubricant composition is employed in the form of an aqueous dispersion having a solids content of expediently 25 percent by weight to 35 percent by weight.
• the dispersion can be prepared using conventional dispersion apparatuses which make high shearing forces possible.
• the viscosity of this dispersion (Rheomat 15, System B, 20° C., speed 5) is between 1500 MPas and 4000 MPas.
• a commercial foam-suppressing compound e.g., a polyalkylene glycol, can be added to the lubricant composition up to an amount of approximately 1 percent.
• the lubricant compositions of the invention are applied to the roller mandrel in the context of the rolling operation by a suitable spraying apparatus for disperse systems, the water evaporating and a lubricating film forming which spreads onto the inner side of the tube blank in the rolling operation and, thus, effectively suppresses carburization.
• Viscosity measurements were made in a Rheomat 15, System B at 20° C. and speed 5.
• the formulations 1 to 5, and the comparison formulation were applied individually into a groove made on the surface of a metallic solid, the groove having the dimensions 20 mm ⁇ 2 mm ⁇ 2 mm.
• the treated solid was then dried in an argon atmosphere for 3 hours at 80° C., then heated in the course of 90° seconds to 1250° C., kept at this temperature for 30 seconds and then allowed to cool.
• a disc-shaped specimen having a thickness of approximately 5 mm was sawed from this solid, encapsulated with an epoxy resin and developed with nital 2% (methanolic nitric acid).
• the sample was then studied by microscopy.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4213767

Family Applications (1)

Country Status (9)

Cited By (4)

Families Citing this family (6)

Citations (15)

Family Cites Families (2)

• 1996
  • 1996-05-27 CA CA002177427A patent/CA2177427A1/en not_active Abandoned
  • 1996-05-27 JP JP8131787A patent/JPH08325584A/ja active Pending
  • 1996-05-28 BR BR9602501A patent/BR9602501A/pt not_active Application Discontinuation
  • 1996-05-29 DE DE59602523T patent/DE59602523D1/de not_active Expired - Fee Related
  • 1996-05-29 EP EP96108502A patent/EP0745661B1/de not_active Expired - Lifetime
  • 1996-05-29 US US08/657,029 patent/US5661116A/en not_active Expired - Fee Related
  • 1996-05-29 AR ARP960102783A patent/AR002138A1/es unknown
  • 1996-05-29 AT AT96108502T patent/ATE182613T1/de not_active IP Right Cessation
  • 1996-05-30 CN CN96108500A patent/CN1063478C/zh not_active Expired - Fee Related

Patent Citations (15)

Non-Patent Citations (2)

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